Friday, December 10, 2010

This week in nanotechnology - December 10, 2010

Taking a leaf from animals like dolphins and pilot whales that are known to have anti-fouling skins, researchers are using nanotechnology to create anti-bacteria plastic 'skins' with nanoimprint technology  – synthetic, chemical-free, anti-bacterial surfaces. The surfaces can reduce infections caused by pathogens such as S. aureus and E. coli and can be used on common plastics, medical devices, lenses and even ship hulls. Conventional methods for preventing bacterial surface attachment may use potentially harmful metal ions, nanoparticles, chemicals or UV-radiation.

Chemists have refuted a basic postulate of Förster theory, which describes energy transfers between pigment molecules, such as those that underlie photosynthesis. A revised version of the theory could have an impact on the design of optical computers and improve the efficiency of solar cells.

Viruses have a bad rep - and rightly so. The ability of a virus to quickly and precisely replicate itself makes it a destructive scourge to animals and plants alike. Now, researchers are turning the tables, harnessing and exploiting the "self-renewing" and "self-assembling" properties of viruses for a higher purpose: to build a new generation of small, powerful and highly efficient batteries and fuel cells.

Researchers have shown that a magnetically polarised current can be manipulated by electric fields. This important discovery opens up the prospect of simultaneously processing and storing data on electrons held in the molecular structure of computer chips - combining computer memory and processing power on the same chip.

Researchers have moved a step closer to creating robust, three-dimensional microbatteries that would charge faster and hold other advantages over conventional lithium-ion batteries. They could power new generations of remote sensors, display screens, smart cards, flexible electronics and biomedical devices. The batteries employ vertical arrays of nickel-tin nanowires perfectly encased in PMMA, a widely used polymer best known as Plexiglas.

Even smaller batteries - the world's smallest battery, as a matter of fact - consists of a single tin oxide nanowire anode 100 nanometers in diameter and 10 micrometers long, a bulk lithium cobalt oxide cathode three millimeters long, and an ionic liquid electrolyte. The device offers the ability to directly observe change in atomic structure during charging and discharging of the individual "trees."